Microparticulation of a substance brings about extreme increase of surface area. Microparticulation of a substance thus provides a merit that properties unique to the substance are exhibited readily. Also, in a case of a poorly soluble or insoluble substance, microparticles formed by microparticulation of the substance can be put in a state of pseudo-dissolution in a solvent such as a water (a state where the microparticles, although being suspended in the solvent, appear to be pseudo-dissolved due to the lack of light scattering).
As a conventional microparticulation method, there is known the method disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-113159). This document discloses a method of producing microparticles of organic pigments and condensed polycyclic aromatic compounds by illumination by a laser light. Microparticulation of organic compounds by laser light illumination is also described in Non-Patent Documents 1 to 3.    Patent Document 1: Japanese Patent Application Laid-Open No. 2001-113159    Non-Patent Document 1: Y Tamaki et al., “Tailoring nanoparticles of aromatic and dye molecules by excimer laser irradiation”, Applied Surface Science Vol. 168, p. 85-88 (2000)    Non-Patent Document 2: Y Tamaki et al., “Nanoparticle Formation of Vanadyl Phthalocyanine by Laser Ablation of Its Crystalline Powder in a Poor Solvent”, J. Phys. Chem. A 2002, 106, p. 2135-2139 (2002)    Non-Patent Document 3: B. Li et al., “Enhancement of organic nanoparticle preparation by laser ablation in aqueous solution using surfactants”, Applied Surface Science Vol. 210, p. 171-176 (2003)